1b. Approach (from AD-416):
This project involves eight scientists (8 SYs) and many collaborators that represent a broad range of disciplines focused on the long-term, 10- to 12-year goal of developing sustainable strategies for both irrigated and dryland crop production systems for the MonDak region of eastern Montana and western North Dakota. The ASRU is organized to address basic and applied research issues using an interdisciplinary team approach where multiple hypotheses are tested in four large “Unit Projects.” The “Unit Project” objectives are designed to encompass cropping system development, concurrent development and application of “metrics” or indicators of system performance, and the assessment process by which systems are evaluated and judged. There is considerable overlap, but responsibilities can be generally divided into two broad, overlapping categories with four scientists (Allen, Evans, Lartey and Stevens) primarily examining the systems aspects, and four scientists (Caesar-TonThat, Jabro, Vice-Lenssen and Sainju) focusing their research on developing and evaluating various metrics of cropping system performance. These Unit projects focus on biologically diverse cropping systems. Biological control research (Obj. 2) of two plant diseases spans both dryland (Obj. 3) and irrigated (Obj. 1) systems. Two of the Unit’s major, long-term (6-9 yrs) dryland team projects were completed in 2011 and 2012, respectively and their replacement projects will start FY 2013. One new irrigated team project started in the spring 2012. Another irrigated study was started in 2010. Each these Unit projects will be replaced by a new Unit project as they are completed.

3. Progress Report:
Data from all 2011 irrigated and dryland research projects were analyzed and statistically summarized in preparation for presentations and publications. 2012 data were collected from all projects and prepared for analyses during the winter months. Several manuscripts and book chapters were submitted and published, and presentations made to producers and the scientific community. Research continued on 5 long term dryland cropping systems projects with varying levels of cropping intensity and management that evaluate the interactive effects of tillage, diversification, and cultural management practices on crop yield, competitiveness with weeds, water use, and N cycling and N use efficiency in no till rotations replacing summer fallow. 2012 was the final year for a 9-year dryland project evaluating interactions of management and various rotations of spring wheat, corn, barley and pea. A 6-year study of the effects of tillage, cropping sequence, and N fertilization on dryland malt barley and pea yields and greenhouse gas emissions was completed. A second 6-year study was completed of the effects of irrigation, tillage, crop rotation, and N fertilization on soil C and N sequestration and greenhouse gas emissions.
A new team project was established in spring 2012 to evaluate irrigated cropping system diversity including various late season cover crops and tillage practices on crop yield, weed and disease incidence, soil quality and carbon sequestration. Short-term trials were established to evaluate potential production of several oilseeds for the region and to evaluate the potential of several late season cover crops at two dryland research sites
Work continued on 1) evaluating alternative irrigated cropping systems and determining best management practices for nutrients including N fertilization for strip till sugarbeet, P management irrigated sugarbeet and C and N cycling in irrigated cropping systems; 2) evaluating impacts of N fertilizer rate on the biomass production potential and greenhouse gas emissions of various cool and warm-season perennial grasses;. 3) comparing 2-year irrigated sugarbeet/malt barley rotations to 3-year rotations that also include legume and/or bioenergy crops; and 4) evaluating yield effects due to lateral distances between the irrigated sugarbeet plant and banded preplant fertilizer under strip tillage. Field evaluations of various electronic soil moisture sensors for irrigation scheduling and management were continued. Final soil and plant data collection for a 4-yr tillage depth study on sugarbeet was completed. On-going studies were evaluating biological control of net blotch disease on irrigated and dryland barley and biocontrol of Cercospora leaf spot disease of sugarbeet by the beneficial fungal pathogen L. arvalis.
Various researchers collaborated with the Bureau Land Management to evaluate effects of fairy rings on soil aggregation and communities of native grasses in rangeland of Eastern Montana. Modeling agricultural systems at both dryland and irrigated sites using RZWQM2 model is continuing in collaboration with researchers in Ft. Collins, CO.

4. Accomplishments
1. Biodiesel crops such as Juncea canola are promising replacements for fallow in dryland durum rotations. Identifying suitable cropping alternatives to fallow can increase acreage for crops that can be used as biodiesel and jet fuel feedstock. These potential cropping systems need to efficiently use nitrogen (N) fertilizer, which is a major input expenditure. USDA researchers at Sidney, MT investigated N use and efficiency of three oilseeds as replacement for fallow in 2-year durum rotations. Results from the five-yr study suggested that in semi-arid areas, juncea canola could be a suitable alternative to fallow in 2 year durum rotations. Under the study, growing juncea canola in place of fallow did not affect the following year’s durum yield meaning producers can expect to maintain existing profits from their wheat production while adding additional profit from a new cash crop. Because a significant number of fallowed acres are available in semi-arid regions, the nation could also benefit through an increased supply of oilseed feedstocks for biodiesel production which could help reduce our dependence on imported oil, without impacting existing food production.

2. Molecular markers developed for quick detection of spot form Net blotch disease. The unexpected arrival of a new spot form of net blotch (a fungal disease affecting malting barley) caught producers in western North Dakota and eastern Montana off guard in 2011, resulting in yield losses as high as 70% in some areas. To help address the problem in the future, Sidney, MT ARS scientists quickly developed new molecular tools (employing gene sequencing technology and antibody detection) that can be used to identify the disease presence within 24 hours, rather than the two or more weeks needed previously. The rapid identification of the disease gives producers time to apply fungicides and other control measures needed to prevent spread of the disease and to preserve production and profits. Sidney ARS researchers have already produced a similar molecular tool for identifying another important fungal disease, Cercospora leaf spot in sugarbeet, and have worked with industry to ensure widespread distribution of the new tools across the nation and beyond.

3. Fairy rings found to enhance soil structure and boost western wheatgrass production. Stimulation of plant productivity in fairy rings caused by the fungus Agaricus lilaceps has been reported, but little is known about factors aiding that productivity, particularly with respect to production of western wheatgrass, a desirable native forage. In collaboration with the Bureau of Land Management, Sidney, MT ARS scientists studied soils and plants in three concentric sampling zones (outside the ring, inside the ring and the ring itself) caused by fairy rings in Eastern Montana rangeland. ARS scientists found that the activity of the basideomycete fungi associated with the actual fairy ring, versus the zones in or outside the ring, was primarily responsible for enhancing soil quality and influencing beneficial bacterial communities that together stimulated growth of the desired western wheatgrass within the ring. Consequently, encouraging the growth of fairy rings could increase forage availability in Montana rangelands.

4. New cropping system identified to mitigate greenhouse gas emissions while maintaining crop yield. Currently, agricultural activity accounts for an estimated six percent of greenhouse gas emissions (carbon dioxide, nitrous oxide and methane) contributing to global warming in USA. Information is needed on management practices that can help mitigate agricultural greenhouse gas emissions in the semiarid Northern Great Plains region which can be readily adopted by irrigated and dryland producers without the need for new equipment or technology. Scientists at ARS, Sidney, MT evaluated the effects of tillage, crop rotation, N fertilization, and irrigation on soil greenhouse gas emissions from 2008 to 2011 under dryland and irrigated cropping systems. Their study identified a no-tilled malt barley – pea rotation with nitrogen fertilization between 0 and 80 kg N/ha as a promising rotation option for producers in the region. Results suggest that a no-tilled malt barley-pea rotation with reduced rate of nitrogen fertilization could be used as a management option to mitigate greenhouse gas emissions, while still sustaining malt barley yield, and quality. Farmers thus may practice good environmental stewardship by adopting a no-tilled malt barley- pea rotation in either dryland or irrigated farmland.

5. Sheep grazing can help lower agricultural greenhouse gas emissions. USDA-ARS scientists from Sidney, MT collaborated with scientists from Montana State University to show that using sheep to control weeds during fallow periods of crop rotations may also have beneficial effects on greenhouse gas emissions. Currently, agriculture contributes about six percent of the greenhouse gas emissions known to be contributing to global warming in USA. A two-year study showed that sheep grazing has potentially no adverse impact on greenhouse gas emissions compared to the herbicide method of weed control under dryland cropping systems while still maintaining crop yield and quality. Less intensive sheep grazing with reduced nitrogen fertilization rates can be used to mitigate greenhouse gas emissions and sustain crop yields. Consequently, both animal and crop producers may benefit from sheep grazing during fallow as an effective and potentially inexpensive method of weed control that not only can sustain crop yields, but also mitigate greenhouse gas emissions.

6. Conservation tillage can benefit sugarbeet farmers. As input costs for fuel, fertilizer and labor continue to increase, producer profits are being squeezed. Sidney MT ARS scientists have shown that new management techniques can help reduce those costs. For example, ARS scientists at Sidney, MT have verified that tillage practices affect soil-water-plant ecosystems and can impact soil properties, plant growth, crop yield and quality of sugarbeets. A 4-year study of three tillage practices was conducted on a sandy loam soil in western North Dakota to determine whether conservation tillage practices, including no-till, impacted sugarbeet yields. Under the study, tillage had no significant effect on sugarbeet root and total sucrose yields, which means sugarbeet farmers can lower their input costs (energy, fuel, labor and time) by using conservation tillage thereby reducing cropping costs and increasing profitability. In addition, conservation tillage can help farmers maintain better soil health and quality (through improved soil water retention, soil infiltration, increased organic matter content, and reduced erosion), contributing to more sustainable or even increased crop yields in the future.

7. Maintaining sugarbeet, malt barley and potato yields with lower input costs. The impact of irrigation frequency on yields and producer profitability have not been fully explored in sandy soils in semi-arid regions. Successful irrigation management is one of the most important agronomic practices for achieving profitable yield and maximizing crop water productivity (CWP) while maintaining environmental quality by minimizing water losses to runoff and deep drainage. USDA-ARS scientists at Sidney, MT completed a seven year study comparing irrigation frequency on crop water use (CWU) and CWP in sugarbeet, malt barley and potatoes under self-propelled automated sprinkler systems. No significant differences in yields, CWU, or CWP for sugarbeet (root and sucrose), malt barley or potatoes due to irrigation frequency were found on sandy loam soils. Thus, conventional low frequency irrigation can sustain yields as well as high frequency irrigation practices. Incorporation of this practice can improve water use, and reduce leaching and input costs for farmers using self-propelled automated sprinkler systems on sandy soils.